M111

Introduced in 1992 in the 200 E and 220 E, the M111 was the first Mercedes-Benz four built in volume with a four-valve head — the M102 had only ever had one in the rare 190 E 2.3-16 and its Evolution derivatives. Twin chain-driven camshafts acted on hydraulic bucket tappets, most versions gained two-stage intake cam phasing and knock control, and the whole engine was deliberately laid out to be machined on the same equipment as the diesels, so the company could swing capacity between petrol and oil as demand moved.

The supercharged version arrived at the 1995 Frankfurt show in the C 230 Kompressor. Because an Eaton Roots blower has no internal compression it can be bypassed at part load and freewheel almost without cost, which is how Mercedes-Benz claimed roughly a quarter less fuel than a naturally aspirated engine of the same output. A 2000 overhaul changed more than 150 parts, brought Euro 4 and a smaller M45 blower, and the family reached far beyond saloons — the SLK, the V-Class and Vito, the ML 230, the first Sprinter — before the M271 took over.